Regular Expression Tester

Test and validate regular expressions with visual results

Regular Expression

Example: \b\w+\b to match whole words

Regex Options

Global (g) - Match all occurrences

Case Insensitive (i)

Multiline (m) - ^ and $ match line beginnings/endings

Dot All (s) - . matches newlines

Test String

Replacement Pattern (for RegEx replace)

Use $1, $2, etc. to refer to capture groups

Regular Expression Quick Reference

Character Classes

Symbol	Description	Example
.	Matches any character except newline	a.c matches "abc", "a2c", etc.
\d	Matches any digit (0-9)	\d{3} matches "123", "456", etc.
\D	Matches any non-digit	\D+ matches "abc", "!@#", etc.
\w	Matches any word character (a-z, A-Z, 0-9, _)	\w+ matches "abc123", "test_123", etc.
\W	Matches any non-word character	\W+ matches "!@#", " ", etc.
\s	Matches any whitespace character	a\sb matches "a b", "a\tb", etc.
\S	Matches any non-whitespace character	\S+ matches "abc", "123", etc.
[abc]	Matches any of the characters in the brackets	[aeiou] matches any vowel
[^abc]	Matches any character not in the brackets	[^0-9] matches any non-digit

Quantifiers

Symbol	Description	Example
*	Matches 0 or more occurrences	a* matches "", "a", "aa", etc.
+	Matches 1 or more occurrences	a+ matches "a", "aa", etc., but not ""
?	Matches 0 or 1 occurrence	colou?r matches "color" and "colour"
{n}	Matches exactly n occurrences	\d{3} matches "123", "456", etc.
{n,}	Matches n or more occurrences	\d{2,} matches "12", "123", etc.
{n,m}	Matches between n and m occurrences	\d{2,4} matches "12", "123", "1234"

Anchors and Boundaries

Symbol	Description	Example
^	Matches the beginning of a string	^abc matches "abc" in "abc123", but not in "123abc"
$	Matches the end of a string	abc$ matches "abc" in "123abc", but not in "abc123"
\b	Word boundary	\bcat\b matches "cat" in "the cat sat", but not in "category"
\B	Non-word boundary	\Bcat\B matches "cat" in "verification", but not in "the cat"

Regex